<!-- rem相对单位，相对的是根元素的font-size值 -->
<!-- 流式布局
flex布局
rem布局 -->
<!-- <!DOCTYPE html>
<html lang="zh">
<head>
	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
	<style>
		html{
			font-size: 50px;
		}
		div{
			width: 10rem;
		}
	</style>
</head>
<body>
	<div>你是谁</div>
</body>
</html> -->
<!-- <!DOCTYPE html>
<html lang="zh">
<head>
	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
	<style>
		*{
			margin: 0;
			padding: 0;
		}
		.box{
			width: 100%;
			height: 500px;
		}
		.box .one{
			width: 50%;
			height: 50px;
			background-color: red;
			float: left;
		}
		.box .two{
			width: 50%;
			height: 50px;
			background-color: blue;
			float: left;
		}
	</style>
</head>
<body>
	 流式布局，主要针对宽度 -->
	<!-- <div class="box">
		<div class="one"></div>
		<div class="two"></div>
	</div>
</body>
</html> --> 
<!DOCTYPE html>
<html lang="zh">
<head>
	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>rem</title>
<!-- rem   等比例缩放 -->
<!-- 媒体查询  @media 媒体类型 and （媒体特性）{}-->
	<style>
		html{
			font-size: 50px;
		}
		@media screen and (min-width:280px){
			html{
				font-size: 18.66px;
			}
		}
		@media screen and (min-width:320px){
			html{
				font-size: 21.33px;
			}
		}
		@media screen and (min-width:400px){
			html{
				font-size: 26.66px;
			}
		}
		@media screen and (min-width:500px){
			html{
				font-size: 33.33px;
			}
		}
		@media screen and (min-width:650px){
			html{
				font-size: 43.33px;
			}
		}
		@media screen and (min-width:750px){
			html{
				font-size: 50px;
			}
		}
		.content{
			width: 15rem;
			min-width: 280px;
			max-width: 750px;
			margin: 0 auto;
		}
		nav{
			font-size: .6rem;
			width: 4rem;
			height: 6rem;
			background-color: red;
		}
	</style>
</head>
<body>
	<div class="content">
		<nav>
			你是谁
		</nav>
		
		
		
		
		
		
		
	</div>
</body>
</html>